/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.jca.cci.object;

import java.sql.SQLException;
import javax.resource.ResourceException;
import javax.resource.cci.ConnectionFactory;
import javax.resource.cci.InteractionSpec;
import javax.resource.cci.Record;
import javax.resource.cci.RecordFactory;

import org.springframework.dao.DataAccessException;
import org.springframework.jca.cci.core.RecordCreator;
import org.springframework.jca.cci.core.RecordExtractor;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

/**
 * EIS operation object that expects mapped input and output objects,
 * converting to and from CCI Records.
 *
 * <p>Concrete subclasses must implement the abstract
 * {@code createInputRecord(RecordFactory, Object)} and
 * {@code extractOutputData(Record)} methods, to create an input
 * Record from an object and to convert an output Record into an object,
 * respectively.
 *
 * @author Thierry Templier
 * @author Juergen Hoeller
 * @see #createInputRecord(javax.resource.cci.RecordFactory, Object)
 * @see #extractOutputData(javax.resource.cci.Record)
 * @since 1.2
 */
public abstract class MappingRecordOperation extends EisOperation {

    /**
     * Constructor that allows use as a JavaBean.
     */
    public MappingRecordOperation() {
    }

    /**
     * Convenient constructor with ConnectionFactory and specifications
     * (connection and interaction).
     *
     * @param connectionFactory the ConnectionFactory to use to obtain connections
     */
    public MappingRecordOperation(ConnectionFactory connectionFactory, InteractionSpec interactionSpec) {
        getCciTemplate().setConnectionFactory(connectionFactory);
        setInteractionSpec(interactionSpec);
    }

    /**
     * Set a RecordCreator that should be used for creating default output Records.
     * <p>Default is none: CCI's {@code Interaction.execute} variant
     * that returns an output Record will be called.
     * <p>Specify a RecordCreator here if you always need to call CCI's
     * {@code Interaction.execute} variant with a passed-in output Record.
     * This RecordCreator will then be invoked to create a default output Record instance.
     *
     * @see javax.resource.cci.Interaction#execute(javax.resource.cci.InteractionSpec, Record)
     * @see javax.resource.cci.Interaction#execute(javax.resource.cci.InteractionSpec, Record, Record)
     * @see org.springframework.jca.cci.core.CciTemplate#setOutputRecordCreator
     */
    public void setOutputRecordCreator(RecordCreator creator) {
        getCciTemplate().setOutputRecordCreator(creator);
    }

    /**
     * Execute the interaction encapsulated by this operation object.
     *
     * @param inputObject the input data, to be converted to a Record
     *                    by the {@code createInputRecord} method
     * @return the output data extracted with the {@code extractOutputData} method
     * @throws DataAccessException if there is any problem
     * @see #createInputRecord
     * @see #extractOutputData
     */
    @Nullable
    public Object execute(Object inputObject) throws DataAccessException {
        InteractionSpec interactionSpec = getInteractionSpec();
        Assert.state(interactionSpec != null, "No InteractionSpec set");
        return getCciTemplate().execute(
                interactionSpec, new RecordCreatorImpl(inputObject), new RecordExtractorImpl());
    }


    /**
     * Subclasses must implement this method to generate an input Record
     * from an input object passed into the {@code execute} method.
     *
     * @param inputObject the passed-in input object
     * @return the CCI input Record
     * @throws ResourceException if thrown by a CCI method, to be auto-converted
     *                           to a DataAccessException
     * @see #execute(Object)
     */
    protected abstract Record createInputRecord(RecordFactory recordFactory, Object inputObject)
            throws ResourceException, DataAccessException;

    /**
     * Subclasses must implement this method to convert the Record returned
     * by CCI execution into a result object for the {@code execute} method.
     *
     * @param outputRecord the Record returned by CCI execution
     * @return the result object
     * @throws ResourceException if thrown by a CCI method, to be auto-converted
     *                           to a DataAccessException
     * @see #execute(Object)
     */
    protected abstract Object extractOutputData(Record outputRecord)
            throws ResourceException, SQLException, DataAccessException;


    /**
     * Implementation of RecordCreator that calls the enclosing
     * class's {@code createInputRecord} method.
     */
    protected class RecordCreatorImpl implements RecordCreator {

        private final Object inputObject;

        public RecordCreatorImpl(Object inObject) {
            this.inputObject = inObject;
        }

        @Override
        public Record createRecord(RecordFactory recordFactory) throws ResourceException, DataAccessException {
            return createInputRecord(recordFactory, this.inputObject);
        }
    }


    /**
     * Implementation of RecordExtractor that calls the enclosing
     * class's {@code extractOutputData} method.
     */
    protected class RecordExtractorImpl implements RecordExtractor<Object> {

        @Override
        public Object extractData(Record record) throws ResourceException, SQLException, DataAccessException {
            return extractOutputData(record);
        }
    }

}
